Light quark masses in QCD

We study the value of the light quark masses combination mu + md in QCD using both Finite Energy Sum Rules and Laplace Sum Rules. We have performed a detailed analysis of both the perturbative QCD and the hadronic parametrization inputs needed in these Sum Rules. As main result, we obtain mu (1 GeV2 + md (1 GeV2) = (12 ± 2.5) MeV for the running MS masses.